The present invention relates in general to adaptive optical devices, and more particularly, to liquid lenses, and to imaging systems and imaging methods employing the same.
Optical focusing is often a slow process due to the delay inherent in moving mechanically a camera's lens until an image is in focus. Although liquids are considered an exotic choice for lens material, there is interest in liquid lenses for applications in adaptive optics requiring fast response, or for applications that require small or cost effective optics. Liquid lenses advantageously avoid the increased weight and fabrication complexity associated with moving solid lenses. The interface of a liquid lens has good optical qualities because of surface tension, which dominates gravity in the sub-milliliter scale, and provides interfaces that are nearly perfectly spherical and optically smooth down to molecular scales.
The recent surge in the use of images and multimedia in consumer-level wireless communications has fueled the pursuit of lightweight and robust adaptive optics. The desire for such lenses extends beyond cell phones and camcorders, however, to advanced technologies in biomedical sensing and imaging, autonomous air and underwater vehicles for surveillance and defense, microscopy and adaptive lithography for micro-manufacturing, etc.